title: Oxygen optrode for use in a fiber-optic glucose biosensor.
abstract: An optical fiber oxygen sensor, based on the dynamic quenching of the luminescence of tris(1,10-phenanthroline)-ruthenium(II) cation by molecular oxygen, is presented. The complex is adsorbed onto silica gel, incorporated in a silicone matrix possessing a high oxygen permeability, and placed at the tip of the optical fiber. Oxygen has been monitored continuously in the 0-750 Torr range, with the detection limit being as low as 0.7 Torr. The device has been applied to the development of a fast responding and highly sensitive fiber-optic glucose biosensor based on this highly sensitive oxygen transducer. The sensor relates oxygen consumption (as a result of enzymatic oxidation) to glucose concentration. The enzyme is immobilized on the surface of the oxygen optrode; carbon black is used as an optical isolation in order to prevent ambient light and sample fluorescence to interfere. Measurements have been performed in a flow-through cell in air-equilibrated glucose standard solutions of pH 7.0. The effects of enzyme immobilization procedures (including enzyme immobilization on carbon black) as to response times (around 6 min), analytical ranges (0.06-1 mM glucose), reproducibility in sensor construction, and long-term stability have been studied as well.
authors.affiliation: Analytical Division, Karl-Franzens University, Graz, Austria.
authors.forename: M C
authors.initials: MC
authors.lastname: Moreno-Bondi
authors.forename: O S
authors.initials: OS
authors.lastname: Wolfbeis
authors.forename: M J
authors.initials: MJ
authors.lastname: Leiner
authors.forename: B P
authors.initials: BP
authors.lastname: Schaffar
mesh_terms: D015374:Biosensing Techniques; D005947:Glucose / Q000032:analysis*; D055095:Optics and Photonics / Q000295:instrumentation*; D010100:Oxygen / Q000032:analysis*
chemical_list: D005947:Glucose; D010100:Oxygen